Edit/Update การเขียน ASP.NET กับ MS SQL2005 ในการเรียกข้อมูลจากฐานข้อมูลมาแก้ไข ช่วยหน่อยครับ

    void btnSave_Click(Object sender, EventArgs e)        			
	{
		strSQL = "UPDATE customer SET " + 
		" CustomerID = '"+ this.txtCustomerID.Text +"' " + 
		" ,Name = '"+ this.txtName.Text +"' " + 
		" ,Email = '"+ this.txtEmail.Text +"' " + 
		" ,CountryCode = '"+ this.txtCountryCode.Text +"' " + 
		" ,Budget = '"+ this.txtBudget.Text +"' " + 
		" ,Used = '"+ this.txtUsed.Text +"' " + 
		" WHERE CustomerID = '" + Request.QueryString["CustomerID"] + "' ";

		objCmd = new SqlCommand();
		objCmd.Connection = objConn;
		objCmd.CommandText = strSQL;
		objCmd .CommandType = CommandType.Text;
		
						
		this.pnlAdd.Visible = false;

		try
		{
			objCmd.ExecuteNonQuery();
			this.lblStatus.Text = "Record Updated";
			this.lblStatus.Visible = true;
		}
		catch (Exception ex)
		{
			this.lblStatus.Text = "Record can not update";
		}

    }